diff --git a/src/vs/platform/environment/node/argv.ts b/src/vs/platform/environment/node/argv.ts
index 6a32ff613a1abdff4555d301689b15590947caae..38e7ca5ad332ec5f97f63b7d17be10875b23ae47 100644
--- a/src/vs/platform/environment/node/argv.ts
+++ b/src/vs/platform/environment/node/argv.ts
@@ -142,7 +142,7 @@ export const OPTIONS: OptionDescriptions<Required<ParsedArgs>> = {
 	'list-extensions': { type: 'boolean', cat: 'e', description: localize('listExtensions', "List the installed extensions.") },
 	'show-versions': { type: 'boolean', cat: 'e', description: localize('showVersions', "Show versions of installed extensions, when using --list-extension.") },
 	'category': { type: 'string', cat: 'e', description: localize('category', "Filters installed extensions by provided category, when using --list-extension.") },
-	'install-extension': { type: 'string[]', cat: 'e', args: 'extension-id | path-to-vsix', description: localize('installExtension', "Installs or updates the extension. Use `--force` argument to avoid prompts.") },
+	'install-extension': { type: 'string[]', cat: 'e', args: 'extension-id[@version] | path-to-vsix', description: localize('installExtension', "Installs or updates the extension. Use `--force` argument to avoid prompts. The identifier of an extension is always `${publisher}.${name}`. To install a specific version provide `@${version}`. For example: 'vscode.csharp@1.2.3'.") },
 	'uninstall-extension': { type: 'string[]', cat: 'e', args: 'extension-id', description: localize('uninstallExtension', "Uninstalls an extension.") },
 	'enable-proposed-api': { type: 'string[]', cat: 'e', args: 'extension-id', description: localize('experimentalApis', "Enables proposed API features for extensions. Can receive one or more extension IDs to enable individually.") },